Only ever owned a Hasselblad 503cx, pretty much a perfect camera, lenses are easy to come by and fairly inexpensive. The back system works great and is foolproof.

The SL66 is very attractive though, and having movements built in is very cool. I'd check out how much the SL66 with the lens you want will be, I expect it may end up being a lot more than a Hasselblad.